I found that studying for the ATPLs was far more intensive than for my degree course, and there's no "continuous assessment", so everything depends on your performance on exam day. The other big difference between the courses is a lack of essay-writing and practical work for the ATPLs - they're all about cramming millions of facts into the brain in a short space of time. Personally, I found the degree course and its leisurely pace easier than the ATPLs.
Should say that mine was a science degree, not aeronautical.